1. Technical Field
The present invention relates to an electronic apparatus, and in particular, to an electronic apparatus equipped with a recording medium container into which a magnetic hard disc, which serves as a magnetic recording medium, is detachably contained.
2. Related Art
Recently, a navigation system, which is an electronic apparatus that can be handled directly by crews, mounted on a car has become popular. A conventional navigation system uses an information recording medium to store map data, which is for instance a CD (Compact Disc)-ROM or a DVD (Digital Video Disc or Digital Versatile Disc)-ROM. A recent trial is that an information recording medium, such a CD-ROM or DVD-ROM, is replaced by an inexpensive, higher-memory-capacity, and rewritable hard disc (i.e., hard disc unit) to store map data therein.
In the case that the hard disc can be mounted, there are many advantages such that map data are easier to be updated because user's individual data as well as map data can be stored due to a large capacity of the memory. On the other hand, a problem concerning static electricity has been pointed out. To be specific, it is frequently required that users have to remove a hard disc (i.e., a hard disc unit; a casing in which a hard disc medium is incorporated) from a navigation system to rewrite its old map data into new ones. The hard disc unit of which map data have been updated is again loaded into the navigation system. During such unloading and loading operations, static electricity will be to some extent accumulated on the user's body surface. The static electricity is transferred and charged onto the outer surface of the hard disc unit, which may have undesired influence on data stored on the hard disc.
If such charged hard disc unit is loaded, the electric charge on the hard disc unit may create high voltage such hat it is applied to electronic parts mounted on a substrate of the hard disc unit. Due to the application of the high voltage, there is a possibility that the electronic parts are damaged.
In addition, there is a drawback resulted from the fact that the conventional navigation system is provided with no means for preventing erroneous operations to its power supply. Usually, after removing a dressed cover detachably placed at a disc insertion inlet of the navigation system, a user unloads a hard disc unit therefrom to rewrite new map data to its hard disc. The user then loads the hard disc unit into the navigation system, before attaching the dressed cover onto the disc insertion inlet. In the absence of any means for preventing erroneous operations to the power supply of the navigation system, the foregoing unloading and loading operations may cause various problems.
A practical problem may arise when the hard disc unit is loaded or unloaded to or from the navigation system with the navigation system powered. That is, such unloading or loading operations may happen to spoil data written on the hard disc. Moreover, it is pointed out that if the navigation system is powered with no hard disc unit loaded, the system may operate erroneously.